Assembly of Abundant and Rare Bacterial and Fungal Communities in Different Typical Forest Types in the Zhongtiao Mountains

Soil microorganisms play an important role in maintaining the functioning of terrestrial ecosystems. Soil microbial communities usually contain both abundant and rare microorganisms. However, in forest ecosystems, the differences in the functions and assembly processes of abundant and rare microbial taxa in soils between planted pure and mixed forests are currently unknown. In this study, four different forest types in the Zhongtiao Mountains were selected, and the diversity and assembly processes of abundant and rare microbial communities in their soils were quantitatively analyzed. The results show that there are differences in the diversity and assembly processes of abundant and rare microorganisms in the four forests. Significant differences in the α-diversity (Shannon index) of abundant bacteria (<i>p</i> = 0.019) and rare fungi (<i>p</i> = 0.049) were obtained in the four forests. The assembly of abundant bacterial and fungal communities in the four forest types was mainly influenced by stochastic processes, the assembly of rare bacterial communities was mainly influenced by deterministic processes, and the assembly of rare fungal communities was influenced by a combination of deterministic and stochastic processes. Planted mixed forests increase the relative contribution of deterministic processes in the assembly of rare fungal communities compared to planted pure forests. This study determined the relative contributions of deterministic and stochastic processes in the assembly of abundant and rare microbial communities among different forest types, providing a theoretical basis for forest management in mixed forests.